At present, the display technology has been widely applied to display of televisions, cell phones and public information, and display panels useful for displaying pictures are also diverse, and are capable of displaying rich and colorful pictures. However, no matter it is a thin film transistor liquid crystal display panel (TFT-LCD) or an organic light emitting display panel (OLED), they all need to be controlled by drive integrated circuits (ICs). Functions of line sequence scanning and frame-by-frame refresh are achieved by taking control of a display panel with driving ICs, so that image data input to the display panel can be refreshed in real time, and then the dynamic display is realized. A source drive IC is responsible for receiving image data, and for caching of image data and conversion from digital signals to analog signals, and eventually, the converted signals will be transmitted to data lines of the display panel by an output buffer. A gate drive IC is responsible for the implementation of progressive scanning, and gate-line scan signals for turning on row by row are generated by it for the purpose of timing control. Pixel switches will be turned on under the control of a gate-line scan signal for each row after it is applied to a corresponding gate line, so that image data enter storage capacitors of pixels in this row, and the normal display of an image is finally realized.
Generally, the design of a gate drive IC is relatively simple, and its function is relatively single. With the development of flat panel display technology, those skilled in the art start to exploit an edge of a display panel for establishment of a gate integrated drive circuit, so as to realize the function of a gate drive IC. With such a design, the separate provision of a gate drive IC in a frame region of the display panel can be omitted, in favor of the realization of a narrow frame design of the display panel, and meanwhile the production cost of related products is reduced.
A gate integrated drive circuit includes a plurality of shift registers, each of which corresponds to one gate line, and which are arranged in series, and a trigger signal that is transferred level by level exists between two adjacent shift registers. After a trigger signal is received by each shift register, it outputs a gate-line scan signal to a corresponding gate line, and transmits the trigger signal to a unit circuit at the next level. However, in the actual application process of shift registers, owing to existence of tiny particles, or improper arrangement of an interlayer circuit in the production process of a display panel, the following situation may occur: a trigger signal cannot be generated by a shift register at a certain level, or an error trigger signal is output by a shift register at a certain level. This will result in the fact that all shift registers subsequent to this level cannot receive a correct trigger signal, giving rise to interruption of scanning of the display panel, and consequently, full-screen scanning of the display panel cannot be realized.
Aiming at the problem that the interruption of scanning easily occurs to shift registers, such a manner that gate integrated drive circuits are bilaterally arranged is adopted in the prior art. That is, as illustrated in FIG. 1, one group of gate integrated drive circuits is provided at either end of gate lines, respectively, shift registers in each group of gate integrated drive circuits are connected to corresponding ones of ends of gate lines, and two shift registers are used for jointly driving one gate line, so as to ameliorate the problem that the interruption of scanning easily occurs to shift registers. If the interruption of scanning occurs to a shift register at one end of a gate line, then a shift register at the other end of the gate line outputs a scan signal to the gate line. However, a hidden danger of being unable to run full-screen scanning cannot be completely eliminated by this bilateral arrangement manner stated above, and the reason is that the problem of scanning interruption may occur to a shift register at either end of the gate line. For example, as illustrated in FIG. 1, when a second level shift register in gate integrated drive circuits at either end of gate lines cannot normally output a trigger signal to the next level in its neighborhood, every shift register subsequent to the second level shift register cannot receive the trigger signal, and in turn, cannot output a scan signal to a gate line connected thereto, and thus, full-screen scanning cannot be realized by the display panel. Therefore, which row the display panel can be successively scanned through is dependent on which one of two ends of gate lines has more shift registers for successively and normally driving the gate line scanning. So, full-screen scanning of the display panel is still unable to be guaranteed in such a way that gate integrated drive circuits are bilaterally arranged.
Hence, how the full-screen scanning of a display panel can be effectively guaranteed is an urgent problem to be solved by those skilled in the art.